1. Field of the Invention
The invention relates to sputtering systems and somewhat more particularly to a method and device for attaching target bodies onto cooling plates for sputtering systems.
2. Prior Art
German Published Application No. 29 33 835, generally equivalent to U.S. Pat. No. 4,341,816, both of which are assigned to the instant assignee, describes and claims a method for attaching target bodies composed of select target material onto cooling plates for sputtering systems wherein an adhesive material compatible with the target material, for example composed of Ni; Ni/Cr mixtures, 80/20 Ni/Al mixtures; Ni/Al/Mo mixtures; Al/bronze mixtures; Mo; W; Al-Si mixtures; Zn; Cu; Cu/glass mixtures; etc. is applied, preferably via plasma spraying, onto a surface of a target body and subsequently, a relatively thick solderable layer, for example composed of Cu; Cu/glass mixture; silver, etc. is coated, preferably via plasma spraying, onto the adhesive layer. The so-coated surface of the target body and a corresponding surface of a cooling plate are then joined or attached to one another by a soft solder layer.
In this manner, practically all standard target materials, such as non-solderable metallic, glass, ceramic, oxide, silicon or graphite target materials as well as directly solderable target materials can be attached to cooling plates with good adhesion and good thermal contact between a select target body and a cooling plate. However, it has been noted that the attachment joint or connection produced in this manner is not absolutely free of bubbles and pores. Further, in many instances, oxide layers existing on the pre-soldered surfaces of a target body and cooling plate can cause voids or the like in the cross-section of the connecting solder joint.